That, of course, assumes you use it often enough to thus prevent it from going bad...

Every petcock-equipped motorcycle I've ever owned had a steel tank. Dri-gas and/or fuel-stabilizer were the only things that kept those blasted things from rusting right through after a couple Seattle winters.

I can't speak for anyone else, but I've always found air and heat to work real satisfactory in my experience. A snug container to keep it in (briefly) seems to add a certain oomf to the resolution too.